pginstaller - pginst: Check if the specified user has admin privileges,

Log Message:
-----------
Check if the specified user has admin privileges, and refuse to run in that case. Otherwise, we installed sometihng
thatdidn't work. 

Two different implementations - one "secure" for Windows XP and newer that is identical to the one in the backend, and
onefor 2000 that can be tricked by putting group-in-group-in-domain-in-group or something like that. Not likely though,
inmost cases it should catch it. 

Modified Files:
--------------
    pginst/ca:
        pginstca.c (r1.13 -> r1.14)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pginstaller/pginst/ca/pginstca.c.diff?r1=1.13&r2=1.14)
        pginstca.h (r1.1 -> r1.2)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pginstaller/pginst/ca/pginstca.h.diff?r1=1.1&r2=1.2)
        user.c (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pginstaller/pginst/ca/user.c.diff?r1=1.2&r2=1.3)